The call came about 2:45 a.m., exactly four weeks ago. Ryan Brooker was at home in Shelburne, Vt., and Tufts Medical Center in Boston was telling him that doctors had found him a new heart, that he needed to come to Boston, that his window would last only a few hours.

“It’s your time,” he recalls telling himself.

Five hours later, he was sitting in bumper-to-bumper traffic, on Interstate 93 just north of Medford, feeling his opportunity for the life-saving operation fading with each passing minute.

What came next was the type of public service that still surprises Brooker and his family, one he recounted at a reunion with his rescuers Monday. A Massachusetts State Police cruiser pulled up to the rear of his car. Another pulled in front, lights flashing and sirens blaring. A third would meet them at the Interstate 93 tunnel, to lead them into downtown.

And Brooker’s father, John, was now driving faster than he would ever want to do again, the elder Brooker says.

If troopers want to do anything in their career, it’s save a life. So when staff at Tufts Medical made the desperate call for troopers to escort Brooker’s car into Boston, that his future depended on it, this became a story about police service, about doctors and nurses, and about a young man thankful to simply live his life again.

“What you guys have done, quite literally, helped save my life . . . that’s all I can really say,” Brooker told the troopers in the reunion at the hospital Monday, handing them a thank you card.

“It’s good to see you like this, you know,” Trooper T.J. Hannon responded, seeming to be lost in his words.

“What an amazing gift,” John Brooker told the roomful of doctors, nurses, and troopers.

The beginning of the story dates back nine years. Brooker, then a 25-year-old college graduate with a degree in finance, was in the banking industry, “doing the career thing,” when he contracted a rare virus that led to progressive heart failure.

He was hospitalized for several months, took medication, underwent therapy, and rebounded for a bit and worked at a restaurant. But he knew he would never truly be better. He would only get worse. In the last year, he sought treatment at Tufts, hoping doctors had options for him. In August, his condition deteriorated to the point that a ventricular assist device was implanted, a bridge before a heart transplant, and he was designated as a high priority for a new organ, based on his age, condition, and years suffering.

On Nov. 26, he got the call at home in Shelburne, a small suburb of Burlington. He had been told that, ideally, a heart should be transplanted within four hours, and he was sure he could make it to Boston quickly. Until he saw the traffic.

“The closer we got to Boston, the clearance got less and less,” recalled his father. “At one point, it became a complete stop.”

The hospital called three times about their whereabouts. “You sense the panic coming in, that you’re going to lose the heart,” John Brooker said. “As a father, you’re helpless . . . you’re just watching the time fly by.”

The hospital staff was growing nervous, too. Colleen Richards, a nurse who had been watching her colleagues trying to coordinate with the Brooks family, decided to call Massachusetts State Police. The agency does not typically provide escorts, for a variety of public safety reasons, but Richards said she wanted to try.

“We’re all in the field of helping people in their most vulnerable state,” she said.

Richards found a welcoming voice on the other end of the line. Lt. John Ward, whose father recently underwent heart surgery at Tufts, understood the seriousness of the call and agreed to direct troopers to Brooker’s car.

“I am just thinking, it’s time-sensitive, we have to get him there quickly, and safely,” said Ward, the commander of the Medford barracks. “We were thinking about saving a life.”

All he knew was that they had a beige car. It was in the Medford area. It had Vermont license plates, and they would move into the breakdown lane so the troopers could find them. By 8:15 a.m., about 15 minutes after Richards made the call, police found the car. And by 8:35 a.m., they were at the hospital.

Trooper Robert Childs located the car and provided the rear escort, while Trooper Peter Kane guided them through a maze of traffic. Hannon met them at the Interstate 93 tunnel and led them into downtown Boston. He did not even know whom they were escorting, or why, until they arrived at the hospital, and nurses rushed Brooker from the car.

“It gives you that feeling, you did it,” Childs said.

Dr. Duc Pham, surgical director of the Heart Failure and Cardiac Transplant Center at Tufts, said the escort was critical to the success of the surgery. In the United States, a quarter-million people suffer from end-stage heart failure, but only about 3,000 transplants happen each year. “This just happened to be a perfect match for him,” Pham said.

Brooker returned to the hospital for a checkup Monday. He said he feels well: He’s no longer tired and sees color coming back to his skin. He is rebuilding muscle strength. He is waiting for whatever happens next.

“It’s just listening to what life is going to give me,” he said.

And in his return trip to Boston, he said, he wanted to thank the doctors, the nurses. And the troopers. “I have a card here for you guys, just to thank you for everything, and what you guys do,” he told Childs and Hannon, shaking their hands.